eurelectricEU Hydropower:Ensuring security of supply byproviding flexibility on a large scaleFlexibility demand will increase significantlyThe EU power sector is making significant strides in decarbonisation,continuously increasingthe share of renewables in the system with a projected 69%of power generation by2030 and a potential increase to 87%by 20402.As variable sources such as wind and solarphotovoltaics(PV)become predominant,the need for flexibility to ensure an efficientutilisation and security of supply must see substantial growth.A recent study conducted by the European Commission's Joint Research Centre3 indicatesthat we are approaching a tipping point where flexibility needs are expected to increaseexponentially,reaching up to 30%of the total electricity demand.Based on the latestdemand projections for 20402,this flexibility requirement could amount to nearly 1,000 TWhper year.Addressing these needs necessitates a concerted effort towards enhancing theelectricity network infrastructure and bolstering flexible supply and demand.Hydropower,as a renewable energy source,assumes a pivotal role in this context byproviding flexible electricity generation and storage capacity on a large scale throughthree distinct power plant types.